Brake for trip-hammers.



E. L. GREENWALD.

BRAKE FOR TRIP HAMMERS.

APPLICATION rum) MAY22, 1913.

1,105,768. Patented Aug.4,1914.

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E. L. GREBNWALD.

BRAKE FOR TRIP HAMMERS.

APPLIOATION FILED MAY 22, 1913.

Patented Aug. 4, 1914.

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EDWARD L. GREENXVALID, OF DINUBA, CALIFORNIA.

BRAKE FOR TRIP-HAll/IMERS.

Specification of Letters Patent.

Application filed May 22, 1913. Serial No. 769,263.

To all ohom it may concern 1 Be it known that I, EDWARD L. Green- WALD, a citizen of the United States, residing at Dinuba, in the county of Tulare and State of California, have invented certain new and. useful Improvements in Brakes for Trip-Hammers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. i

This invention relates to improvements in brakes for trip hammers and the like.

One object of the invention is to provide an automatically operated brake which will positively and quickly stop the hammer or other machine when pressure on the belt controlling mechanism is released. 7

Another object is to provide a brake of this character which will be simple, strong,

durable and inexpensive in construction efficient and reliable in operation and well.

rangement of parts as will be more fully de-.

scribed and claimed.

In the accompanying drawings: Figure 1 is a side view of a trip hammer showing my improved brake applied thereto and in an inoperative position; Fig. 2 is a top plan view thereof; Fig. 3 is a rear endview of the same; Fig.4 is a detail perspective view of the brake and the treadle frame removed from the machine.

In the embodiment of the invention herein the same is shown applied to a trip hammer, 1 denotes the hammer proper which is carried by an operating lever 2 and is thereby brought into engagement with the anvil 3 arranged on the anvil post 1. Revolubly mounted in the base 5 of the machine is the hammer operating shaft 6 which is connected by the usual or any suitable operating means 7 t0 the lever 2 of the hammer, whereby the latter is rcciprocated or swung up and down in the usual manner. Fixed on one end of the drive shaft 6 is a driving pulley 8 with which is engaged a driving belt 9 and on the inner edge of which is formed a braking surface or drumlO.

Mounted in suitable bearings on the base 5 of the machine in rear of the drive shaft 6 is a rock shaft 11 having on one end upwardly projecting spaced crank arms 12 in the ends ofwhich is fixed a shaft 13 on which is revolubly mounted a belt engaging and tightening roller 1 1 which is adapted to be brought into engagement with the adjacent stretch of the belt 9 whereby the latter is tightened and caused to revolve the pulley 8 and the drive shaft and thereby operate the hammer. The rock shaft 11 has fixed on its opposite end an upwardly projecting crank arm 15 and said arm and the inner crank arm 12 of the bolt tightening roller are connected by operating links 16 to bell crank levers 17 which are pivotally mounted on the opposite sides of the base 5 near the forward end of the machine and to the other arms of which are secured the ends of a bail or loop sha ped treadle frame 18 arranged around and projecting forwardly beyond the end of the base as shown. Connected to the crank arm 12 of the belt engaging roller 1a and to the rear end of the base 5 is a roller retracting spring 19 which is designed to retract the belt tightening roller, thus releasing the pressure on the belt which will cause the latter to run loosely on the driving pulley 8. By thus constructing and arranging the belt tightening mechanism as herein shown and described it will be seen that the spring 19 will normally hold the belt tightening mechanism out of operation so that the belt 9 will not operate the hammer until the treadle frame 18 is depressed by the foot of the operator, which operation will swing the crank arms 12 and 15 forwardly thereby bringing the belt tightening roller 1-1 into engagement with the belt as clearly shown in Fig. 1 of the drawing thereby starting the machine.

The foregoing parts may be of the usual or any approved construction and do not form part of the present invention which relates to a brakingmechanism for quickly and positively stopping the machine when the belt tightening mechanism is released and which will now be described.

My improved braking mechanism comprises abrake band 20 which is in the form of a strip of spring metal bent in substantially circular form and which is disposed around the braking surface or drum 10 of the belt pulley 8. The ends of the band 20 have formed thereon angular outwardly projecting apertured lugs 21 and 22. Engaged with the lugs 21 and. 22 is a brake Patented Aug. 4., 1914:. v

secured in. a bracket 24; on the rearend of.

the machine, said end of the rod 23 being.

preferably threaded to receive a nut 25 which holds the same in engagement/With the bracket as clearly shown in Figs. 1 and 2 of the drawing. The forward end. of the rod 23 is preferably bent downwardly to a slight angle and to said angular end of the rod near the bend therein is rigidly secured the lug -21 of the brake band 20, said lug being preferably secured by jam nuts 26 arranged on each side of the lug as shown. The lug 22 on the opposite end of the band 20 is loosely engaged with and slides on the end of the rod 23 thereby permitting the band 20 to expand and disengage the brake drum when .the brake operating mechanism is released.

The brake band is contracted .and tight ened into operative engagement with the brake drum 10 by apush bar or link 27 the forward end of which is pivotally connected to the arm of the adjacent bell crank lever 1? to which the operatinglinlclti of the belt tightening mechanism on, this side of the machine is connected. The rear end of the push bar 27 has formed thereon a right angular apertured lug 28 which has a loose sliding engagement with the end of the anchoring rod 23 and is also engaged with the lug 22 on the free end of the brake band 20 as shown. By thus arranging the push rod 27 it will be seen that when the treadle frame 18 is depressed, said push bar will be retracted on Y the angular end of the anchoring rod 23 by thebell crank lever 17 which will permit the brake band to expand and rele se the brake drum and driving pulley simultaneously with the engagement of the belt tightening roller with the belt shaft. The braking mechanism will not interfere with the operation of the pulley by the belt 9 as long as the treadle 18 is depressed. As soon, however, as the treadle is released by "the operator the spring 19 will immediately retract the. belt tightening mechanism and will. rock the bell crank lever 17 in the proper direction for actuating the push bar 27 which will contract the brakeband 20 or draw the same into tight engagement with the brake drum simultaneously with the loosening of the belt by the retraction of the belt tightening mechanism, thereby quickly and positively stopping the operation of the hammer as will be readily understood.

From the foregoing description taken in connection with the accompanying drawings, the construction nd o ratio ef th invention will be readily understood with- I out requiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted towithout departing, from the principle or. sacrificing any of the advantages of the invention as claimed.

Having thus describedmy inventiomwhat.

I claim is: V

1. in a trip hammer of the class de-' scribed, the combination. with a supporting frame, a driving pulley with belt tightening mechanism therefor mounted in said frame,

of a brake drum fixed on said pulley, a brake anchoring rod securedto sald frame,

an expansible brake band engaged with said brake drum and having one end fixed to. said anchoring rod andfits other end slidably engaged with'said rod, and a push bar having a right angular apertured Bar slidably mountedon said anchormgrodat the rear of th free end- 0f the brake band,

the other end of said push bar being engaged with the operating mechanism of the belt tightener, whereby when the latter is actuated to apply the belt tightening mechanism, the brake band will expand,'and when actuated to. release the belt tightening mechanism, the band will be forcibly brought into operative engagement with the brake drum.

2. In a trip hammer of the class de} scribed the combination with a supporting frame having a driving pulley, a belt tightening mechanism therefor mounted in said frame, of a brake drum fixed on-said pulley, an expansible brake band engaged with said drum and having angular laterally projecting apertured lugs at its 'free'ends, a brake anchoring rod fixed ,to one of said lugs and slidably engaged with the other,

the outer end of said rod being secured to said frame and the forward end thereof bent downwardlyat an angle, apush bar -or link having a laterally, extending apertur-ed ear slidably engaged with said rod at the rear of the sliding lug of said brake band, the other end of said push bar being pivotally connected to the operating mechanism of the belt tightener.

In testimony whereof I have hereunto set my hand in presence of the subscribing Wit- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G." 1 

